Plasma processing apparatus

ABSTRACT

There is provided a plasma processing apparatus including: a chamber; an insulating plate provided in an upper region in the chamber; a ground electrode provided on a sidewall of the chamber and supplied with a ground voltage; and a lower electrode provided in a lower region in the chamber on which a substrate is seated, wherein the lower electrode comprises a plurality of electrodes, and an RF voltage and the ground voltage are alternately supplied to the adjacent two electrodes, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application No. 11/947,610, filed on Nov. 29, 2007, the contents of which is incorporated by reference herein in its entirety, which claims priority to Korean Patent Application No. 10-2006-0124763, filed Dec. 8, 2006, Korean Patent Application No. 10-2007-0085561, filed Aug. 24, 2007 and Korean Patent Application No. 10-2007-0109448, filed Oct. 30, 2007, the contents of which are incorporated by reference herein in their entirety. This application also claims priority to Korean Patent application No. 10-2008-0031042, filed on Apr. 3, 2008 and all the benefits accruing therefrom under 35 U.S.C. 119, the contents of which are herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a plasma processing apparatus, particularly a plasma processing apparatus that removes a variety of impurities on a substrate.

2. Description of the Related Art

Semiconductor elements and flat panel displays are formed by depositing a plurality of thin films on a substrate and etching the films. That is, an element having a predetermined thin film pattern is formed by depositing thin films on a predetermined region of a substrate, mainly in the central region, and then removing a portion of the thin films in the central region of the substrate by etching with an etching mask.

The thin film is deposited on the entire substrate during deposition, whereas an etching target during etching is a portion of the thin film in the central region of the substrate. Accordingly, the rest of the thin film in an edge area of the substrate is not removed and particles are accumulated in the edge area of the substrate as the etching process is continued. Further, since the substrate is typically seated by an electrostatic force or a vacuum force on a substrate holder for supporting the substrate, the substrate and the substrate holder are spaced apart by a predetermined distance so that a gap is formed at the interface. Therefore, the particles and thin films are also accumulated on the entire backside of the substrate.

Therefore, when the process is continued without removing the particles and thin films accumulated on the substrate, the substrate may be deformed or alignment of the substrate may become difficult.

In general, a wet etching and a dry etching are known in the art as methods of removing particles and thin films accumulated on the substrate. The wet etching removes particles on a surface by soaking a substrate in a solvent or a rinse, and the dry etching removes particles by etching the surface with plasma.

Although the wet etching is generally used to remove particles accumulated on the surface of the substrate, it is difficult to selectively remove the particles in the edge area since process management of the wet etching is difficult. Further, the wet etching process results in an increase of the process cost by using a large amount of chemicals and causes many environmental problems such as chemical waste disposal. On the contrary, dry etching removes particles and thin films accumulated around the edge of a substrate using plasma, and may avoid drawbacks of the wet etching. Therefore, in recent years, an apparatus for exposing and etching only an edge area of a substrate is under development.

In the related art, plasma etching devices for etching an edge area of a substrate using plasma as described above have been disclosed in Korean Patent Registration Nos. 10-0433008 corresponding to Korean Patent Publication No. 10-2002-0080955 and Korean Patent Registration No. 10-0442194 corresponding to Korean Patent Publication No. 10-2003-0072520.

According to a device disclosed in Korean Patent Registration No. 10-0433008, a stage has a smaller diameter than a substrate, and a distance between a stage and an insulator is set to be smaller than a distance between a cathode ring and an anode ring. The cathode ring and anode ring are attached to the outsides of the stage and insulator, respectively. In detail, the anode ring is installed around a circumference of the insulator. A view ring is coaxially attached around the circumference of the anode ring so that an edge of the view ring extends to be close to the cathode ring. Therefore, the circumference of the stage is shielded except for a predetermined gap between the stage and the cathode ring. An RF output terminal is connected to the cathode ring. In the above configuration, the cathode ring and anode ring are installed around the circumferences of the stage and insulator, respectively. The diameters of the stage and insulator are smaller that that of a substrate. And plasma is generated by a discharge between the cathode ring and the anode ring. In addition, the view ring is installed around the cathode ring, so that the plasma is applied even to the edge area of the backside of the substrate. Thereby the edge area of the backside of the substrate can be effectively etched using the plasma.

A pair of electrodes, i.e., first and second electrodes for dry etching of a substrate is disclosed in Korean Patent Registration No. 10-0442194. The first and second electrodes are facing each other, and remove impurities on an edge area the substrate by generating plasma. The first electrode includes a first protruding end and a first protrusion. The first protruding end and the first protrusion have a circular shape, and face one side of upper and lower portions of the edge of the substrate. The second electrode includes a second protruding end and a second protrusion. The second protruding end and the second protrusion have the same size as the first protruding end the first protrusion, and face the other side of the upper and lower portions of the edge of the substrate. According to the above configuration, a variety of impurities accumulated on sides and a backside of an edge area of a substrate, not to mention an upper surface, can be removed.

However, in the above configurations in the related arts, a substrate is placed on a substrate holder having a smaller diameter than the substrate, and then a portion of the substrate which is exposed to the plasma is etched by plasma. As such, particles accumulated on an edge area, sides, and a backside of the substrate, in particular, particles accumulated on an edge area of the backside are removed. However, particles accumulated between the substrate holder and the substrate are not easily removed in the above configuration.

SUMMARY OF THE INVENTION

The present invention provides a plasma processing apparatus which effectively removes not only particles on an edge area of an upper surface, sides, and a backside of a substrate, but also particles accumulated in a central region of the backside of the substrate.

In accordance with another exemplary embodiment, a plasma processing apparatus includes: a chamber; an insulating plate provided at an upper region in the chamber; a ground electrode provided on a sidewall of the chamber and supplied with a ground voltage; and a lower electrode provided in a lower region in the chamber on which a substrate is seated, wherein the lower electrode includes a plurality of electrodes, and an RF voltage and the ground voltage are alternately applied to the adjacent two electrodes, respectively.

The electrode to which the RF voltage is applied may be fixed, and the other electrodes may be driven to move up and down.

The electrode to which the ground voltage is applied may be fixed, and the other electrodes may be driven to move up and down.

The electrodes of the lower electrode may be concentric and spaced apart from each other by a predetermined distance.

The electrodes of the lower electrode may include first, second and third electrodes arranged from the center toward the periphery of the substrate. The diameter of the first electrode may be approximately 35 to 55% of the diameter of the third electrode, and the diameter of the second electrode may be approximately 56 to 75% of the diameter of the third electrode.

The electrodes of the lower electrode may include first, second, third and fourth electrodes arranged from the center toward the periphery of the substrate. The diameter of the first electrode may be approximately 35 to 45% of the diameter of the fourth electrode, the diameter of the second electrode may be approximately 46 to 60% of the diameter of the fourth electrode, and the diameter of the third electrode may be approximately 61 to 75% of the diameter of the fourth electrode.

The electrodes of the lower electrode may include first, second, third, fourth and fifth electrodes arranged from the center toward the periphery of the substrate. The diameter of the first electrode may be approximately 30 to 40% of the diameter of the fifth electrode, the diameter of the second electrode is approximately 41 to 50% of the diameter of the fifth electrode, the diameter of the third electrode may be approximately 51 to 60% of the diameter of the fifth electrode, and the diameter of the fourth electrode may be approximately 61 to 75% of the diameter of the fifth electrode.

The plasma processing apparatus may further include a substrate sensor provided on the chamber to sense the substrate, wherein at least one guide hole may be formed in the insulating plate to guide light output from the substrate sensor toward the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:

FIG. 1 is a cross-sectional view of a plasma processing apparatus according to a first exemplary embodiment of the present invention;

FIG. 2 is a perspective view showing a variant of an insulating member provided in the plasma processing apparatus according to the first exemplary embodiment of the present invention;

FIG. 3 is a cross-sectional view showing the insulating member of FIG. 2 attached to a chamber;

FIG. 4 is a cross-sectional view of a first variant of the insulating member provided in the plasma processing apparatus according to the first exemplary embodiment of the present invention;

FIG. 5 is a cross-sectional view of a second variant of the insulating member provided in the plasma processing apparatus according to the first exemplary embodiment of the present invention;

FIG. 6 is a rear perspective view of a gas injector ring shown in FIG. 5;

FIG. 7 is an exploded perspective view of a lower electrode according to the first exemplary embodiment of the present invention;

FIGS. 8 to 11 are schematic cross-sectional views illustrating a process of removing impurities on a side and a backside of a substrate;

FIGS. 12 to 17 are variants of the lower electrode according to the first exemplary embodiment of the present invention;

FIG. 18 is a cross-sectional view of a plasma processing apparatus according to a second exemplary embodiment of the present invention; and

FIGS. 19 and 20 are cross-sectional views illustrating an operation of the plasma processing apparatus according to the second exemplary embodiment of the present invention.

FIG. 21 is a sectional view of a plasma processing apparatus in accordance with a third exemplary embodiment; and

FIG. 22 is an exploded perspective view of a lower electrode shown in FIG. 21.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the invention are described hereafter in detail with reference to accompanying drawings. The present invention, however, is not limited to the embodiments described herein, but may be modified in a variety of ways, and the embodiments is provided only to fully describe the invention and inform those skilled in the art of the aspects of the invention. The same reference numeral indicates the same components in the drawings.

FIG. 1 is a cross-sectional view of a plasma processing apparatus according to a first exemplary embodiment of the present invention. FIG. 2 is a perspective view showing a variant of an insulating member provided in the plasma processing apparatus according to the first exemplary embodiment of the present invention. FIG. 3 is a cross-sectional view showing the insulating member of FIG. 2 attached to a chamber. FIG. 4 is a cross-sectional view of a first variant of the insulating member provided in the plasma processing apparatus according to the first exemplary embodiment of the present invention. FIG. 5 is a cross-sectional view of a second variant of the insulating member provided in the plasma processing apparatus according to the first exemplary embodiment of the present invention. FIG. 6 is a rear perspective view of a gas injector ring shown in FIG. 5. FIG. 7 is an exploded perspective view of a lower electrode according to the first exemplary embodiment of the present invention. FIGS. 8 to 11 are schematic cross-sectional views illustrating a process of removing impurities on a side and a backside of a substrate. FIGS. 12 to 17 are variants of the lower electrode according to the first exemplary embodiment of the present invention.

Referring to FIG. 1, a plasma processing apparatus using reactive ion etching (“RIE”) according to an exemplary embodiment of the present invention includes: a chamber 100; an insulating member 200 disposed at an upper portion inside the chamber 100; a ground electrode 300 provided at an upper portion of a side wall of the chamber 100; a lower electrode 400 on which a substrate G is placed; and a lift member 500 for moving up/down the lower electrode 400.

The chamber 100 is made of aluminum of which surface is anodized. The chamber 100 includes a lower chamber 100 a and a chamber lid 100 b covering the upper portion of the lower chamber 100 a. The lower chamber 100 a is formed in a cylindrical shape with a top open. The shape of the lower chamber 100 a may be changed according to a shape of a semiconductor wafer or a glass substrate. The chamber lid 100 b closes the upper portion of the lower chamber 100 a and hermetically contacts with the upper portion of the lower chamber 100 a to form a predetermined space inside the chamber 100.

A gas supply channel 110 is formed at the upper portion of the chamber 100. The gas supply channel 110 passes through the upper wall of the chamber 100 to feed a reactive gas, and is connected to a gas supplier 120. Therefore, a reactive gas is supplied into the chamber 100 through the gas supply channel 110 from the gas supplier 120. The reactive gas may be one of Ar, CF₄, Cl₂, SF₆, BCl₃ and combinations thereof. A gate 130 through which the substrate G is loaded into the chamber 100 is formed at a sidewall of the chamber 100. The gate 130 opens/closes to load or unload the substrate G into or from the chamber 100. In the above, one gate 130 is formed at the sidewall of the chamber 100. However, another gate may be formed at other sidewall facing the gate 130 of the chamber 100. That is, the substrate G may be inserted through a gate before a process and may be unloaded through the other gate after the process. Exhaust pipes 140 are provided at a bottom of the chamber 100. Reaction by-products, such as particles generated during etching, and gases are exhausted outside the chamber through the exhaust pipes 140. The exhaust pipes 140 may be formed at the lower portions of the sidewalls of the chamber 100, as well as the bottom of the chamber 100.

The insulating member 200 is disposed in an upper portion of the chamber 100, i.e. on the lower surface of the chamber lid 100 b to have a circular plate shape. The insulating member 200 uniformly distributes the plasma generated around the substrate G in the chamber 100, and protects upper inner walls of the chamber 100. A cooling line 210 is provided inside the insulating member 200 to regulate a temperature of the insulating member 200, and connected to a cooling water supplier (not shown). Therefore, cooling water is supplied from the cooling water supplier to the cooling line 210. The cooling water prevents the insulating member 200 from being damaged by the plasma generated in the chamber 100. A coating material, for example Y₂O₃, is coated on an edge area of a lower surface and a sidewall of the insulating member 200 to prevent particles generated in the chamber 100 from attaching to the edge and sidewall.

The insulating member 200 is formed as a single plate shape in the above configuration, but the present invention is not limited thereto. The insulating member 200 may be divided into a plurality of insulating members. Referring to FIGS. 2 and 3, the insulating member 200 may include an inner insulating member 200 a and an outer insulating member 200 b which is coupled to an outer circumference of the inner insulating member 200 a.

The inner insulating member 200 a is formed in a circular plate shape. A first step 202 having an L-shaped cross-section is formed around the circumference of the inner insulating member 200 a. The outer insulating member 200 b is formed in a ring shape having a through hole at the center. A second step 204 having an inverse L-shaped cross-section is formed along an inside edge of the outer insulating member 200 b to correspond to the first step 202 which is formed around the circumference of the inner insulating member 200 a. The outer insulating member 200 b is assembled with the inner insulating member 200 a from above. In detail, the second step 204 of the outer insulating member 200 b is placed on the first step 202 of the inner insulating member 200 a, such that the inner insulating member 200 a supports the outer insulating member 200 b. The inner insulating member 200 a supporting the outer insulating member 200 b is fastened to the lower surface of the chamber lid 100 b by fastening members, such as bolts. As such, the insulating member 200 is fixed to the lower surface of the chamber lid 100 b. The shapes of the first step 202 and the second step 204 are not limited to the above shapes and may be changed into any shapes as long as the outside of the inner insulating member 200 a can be completely coupled to the inside of the outer insulating member 200 b.

According to the above configuration, a coating material is coated only on the lower surface and the side of the outer insulating member 200 b for insulation and preventing attachment of particles, thereby manufacturing cost can be reduced as compared to the conventional insulating member of which entire surface is coated with the coating material. Further, a various outer insulating members 200 b having different sizes can be employed depending on a size of the insulating member 200 to be installed inside the chamber 100.

The insulating member 200 may have the following configuration so that it is attached always to the same position of the lower surface of the chamber lid 100 b. As shown in FIG. 4, a predetermined groove 206 is formed on the upper surface of the inner insulating member 200 a, and a protrusion 102 corresponding to the groove is protruded from the lower surface of the chamber lid 100 b. The groove 206 and the protrusion 102 are formed to have a shape of a looped curve. The groove 206 of the inner insulating member 200 a supporting the outer insulating member 200 b is coupled to the protrusion 102 protruding from the lower surface of the chamber lid 100 b. The inner insulating member 200 a is then fastened to the lower surface of the chamber lid 100 b by fastening members, such as bolts. According to the above configuration, the insulating member 200 is fixed always at the same position on the lower surface of the chamber lid 100 b, such that arrangement time can be saved.

In the above configuration, the groove 206 and protrusion 102 are respectively formed on the insulating member 200 and the chamber lid 100 b to have a shape of the looped curve. However, the present invention is not limited thereto. That is, pluralities of protrusions 102 and corresponding grooves 206 may be separately formed and arranged so that the general shape appears as the looped curve. Further, pluralities of protrusions and corresponding grooves may be formed along the looped curve. Furthermore, although the groove 206 is formed on the inner insulating member 200 a and the protrusion 102 is formed on the lower surface of the chamber lid 100 b, the protrusion may be formed on the inner insulating member 200 a and the predetermined groove may be formed on the lower surface of the chamber lid 100 b. In addition, although the protrusion 102 is formed on the lower surface of the chamber lid 100 b in the above configuration, it is possible to insert an aluminum plate (not shown) between the chamber lid 100 b and the insulating member 200 and form a protrusion on the lower surface of the plate to assemble them.

The insulating member may have the following configuration to reduce the temperature of the upper surface of the substrate during a process. As shown in FIGS. 5 and 6, the inner insulating member 200 a is formed in a circular plate shape and a gas injector ring 209 is disposed on the lower surface of the inner insulating member 200 a. Further, the outer insulating member 200 b is coupled to the outside of the inner insulating member 200 a. The inner insulating member 200 a and outer insulating member 200 b assembled as described above are then attached to the lower surface of the chamber lid 100 b.

A lower groove 207 having a shape of looped circle is formed on the lower surface of the inner insulating member 200 a. A gas line 208 is formed through the inner insulating member 200 a to communicate with the lower groove 207. The gas line 208 is formed through the chamber lid 100 b to communicate with the chamber lid 100 b to which the inner insulating member 200 a is attached. A cooling gas, such as helium, may be supplied through the gas line 208. The gas injector ring 209 is fitted into the lower groove 207 on the lower surface of the inner insulating member 200 a. The gas injector ring 209 is formed in a ring shape with the center cut vertically, and includes a plurality of injection holes 209 a formed along the lower surface. The plurality of injection holes 209 a may communicate with the gas line 208 of the inner insulating member 200 a. Further, the shape of the injection hole 209 a is not limited and may be a circle, a polygon or the like.

When plasma is generated around the backside of the substrate after the process starts, the cooling gas is injected to the upper surface of the substrate through the chamber lid 100 b and the inner insulating member 200 a. In this way, increase of a substrate temperature by the plasma can be prevented.

According to the above configuration, it is possible to prevent a deformation of the substrate caused by the increased temperature of the edge area of the substrate due to the plasma during the process of the substrate. Although the insulating member is cooled by the cooling line, cooling is less effective in vacuum environment because there is no heat conducting medium between the substrate and the insulating member. Therefore, the substrate temperature can be regulated more effectively by such a configuration of the insulating member.

Returning to FIG. 1, the ground electrode 300 is provided to the upper portion of the sidewall of the chamber 100, and formed in a ring shape. The ground electrode 300 includes an inner electrode 310 and an outer electrode 320 each of which is grounded.

The upper portion of the inner electrode 310 is connected to the gas supply channel 110 formed through the upper wall of the chamber 100. And a predetermined space 314 is formed inside the inner electrode 310. Further, a plurality of gas injection nozzles 312 is formed at a side of a sidewall of the inner electrode 310 to be connected to the predetermined space 314. The reactive gas is supplied into the predetermined space 314 formed inside the inner electrode 310 through the gas supply channel 110 formed through the upper wall of the chamber 100. The reactive gas supplied to the space 314 is introduced to the chamber 100 through the gas injection nozzle 312 formed at the sidewall of the inner electrode 310. The outer electrode 320 is formed at an upper portion of a sidewall of the chamber 100, more particularly, adjacent to the lower surface of the inner electrode 310.

With start of the process, the edge area of the substrate G, in detail, the edge area of the upper surface, the side, and the edge area of the backside of the substrate is disposed adjacent to the electrodes 300. That is, the inner electrodes 310 and the outer electrodes 320 of the electrode 300 are disposed adjacent to the edge area of the substrate G to etch away particles and thin films accumulated at the edge area of the upper surface, the side, and the edge area of the backside of the substrate G using the plasma. The inner electrode 310 and the outer electrode 320 may be formed as a single electrode, and a dielectric film may be formed on the surface of the inner electrode 310 and the outer electrode 320 to protect the electrodes 310, 320.

The lower electrode 400 is provided in a lower portion inside the chamber 100. The lower electrode 400 includes a first electrode 410 and a second electrode 420 surrounding the first electrode 410. Further, the lower electrode 400 is connected to an RF power supply (not shown) for supplying power to the lower electrode 400. In addition, an RF matching device (not shown) may be further provided between the lower electrode 400 and the RF power supply. The RF matching device detects impedance in the chamber 100, and generates an imaginary component having an opposite phase to the detected imaginary component, so that the resultant impedance is the same as a real component of the impedance. The RF matching device then supplies a maximum power and thereby generates optimum plasma in the chamber 100. The lower electrode 400 may be formed in a circular or polygonal shape, particularly depending on the substrate G formed of a semiconductor wafer or a glass substrate for a flat panel display. The lower electrode 400 will be described below in detail with reference to the accompanying drawings.

A chuck (not shown) for supporting the substrate G may be further provided on the first electrode 410 and the second electrode 420. The chuck may be an electrostatic chuck using static electricity, but is not limited thereto. The chuck may suck and support the substrate G using a vacuum force or a mechanical force. Further, a cooling line 440 and a cooling water supplier (not shown) which is connected to the cooling lines may be further provided in the first electrode 410 and the second electrode 420 to regulate temperature of the first and second electrodes 410 and 420. Further, a helium line (not shown) may be further provided through the first electrode 410 and the second electrode 420. Helium is supplied through the helium line and regulates temperature of the substrate G.

The lift member 500 includes a first lower lift 510 and a second lower lift 520, and is connected to the lower electrode 400. The first lower lift 510 is connected to the first electrode 410, and the second lower lift 520 is connected to the second electrode 420.

Each of the first lower lift 510 and the second lower lift 520 includes a support 512 and a bellows 514 connected to the support. The first lower lift 510 and the second lower lift 520 form a single lift assembly. A stepping motor 530 is connected to the lift assembly and the first lower lift 510 and the second lower lift 520 are moved up and down by the stepping motor 530. In detail, as the first lower lift 510 moves up, the second lower lift 520 moves down. In contrast, as the second lower lift 520 moves up, the first lower lift 510 moves down, which is similar to a seesaw. The first lower lift 510 and the second lower lift 520 are simultaneously controlled as the single lift assembly in the above configuration. But the first lower lift 510 and the second lower lift 520 may be separately controlled.

The lift member 500 is not limited to the above configuration according to the exemplary embodiment of the present invention, but may be any members capable of moving lower electrode 400 up and down. That is, a cylinder using hydraulic pressure or air pressure, or a linear motor (LM) guide may be used. Further, a combination of the foregoing may be used.

On the other hand, as shown in FIG. 7, a lower electrode 400 according to the exemplary embodiment of the present invention includes an inner electrode of a circular plate shape (hereinafter, referred to as a “first electrode”, 410) and a ring-shaped outer electrode (hereinafter, referred to as a “second electrode”, 420). The first and second electrodes 410 and 420 are coaxially arranged. The inner circumference of the second electrode 420 is spaced apart from the outer circumference of the first electrode 410 by a predetermined distance. The first electrode 410 is formed in a circular plate shape and the second electrode 420 is formed in a ring shape with an opening 422 at the center. The first electrode 410 moves up and down through the opening 422 of the second electrode 420. It is desirable that the outside of the first electrode 410 doesn't interfere with the inside of the second electrode 420. The distance between the outside of the first electrode 410 and the inside of the second electrode 420 may be in a range of 0.1 mm to 10 mm.

A process of removing particles and thin films accumulated on the edge area of the upper surface, the side, the edge area of the backside, and the central portion of the substrate in accordance with the operation of the above configuration is described hereafter with reference to FIGS. 8 to 11.

As shown in FIG. 8, while the substrate G is placed on the first electrode 410, the first lower lift 510 connected to the lower portion of the first electrode 410 is moved up by the stepping motor 530 until the first electrode 410 is spaced apart from the insulating member 200 in the upper portion of the chamber 100 by a predetermined distance. A reactive gas is supplied into the space 314 of the inner electrode 310 through the gas supply channel 110 formed in the chamber lid 100 b from the gas supplier 120, and then, as shown in FIG. 9, flows into the chamber 110 through the gas injection nozzles 312 at a side of the inner electrode 310. A ground potential is applied to the inner electrode 310, the outer electrode 320, and the second electrode 420 and an RF is applied to the first electrode 410, such that plasma P is generated in the chamber 10.

The plasma P is generated in a space surrounded by the first electrode 410, the inner electrode 310 where the ground potential is applied, outer electrode 320, and second electrode 420, in detail, around the edge area of the upper surface, the side, and the edge area of the backside of the substrate G. Because the distance T1 between the insulating member 200 and a central portion of the upper surface of the substrate G is maintained at 1 mm or less, the plasma P is not generated there between. Therefore, the plasma P generated as described above removes particles and thin films accumulated on edge area of the upper surface, the side, and the edge area of the backside of the substrate G.

As shown in FIG. 10, while the substrate G is placed on the first electrode 410, the first lower lift 510 connected to the lower portion of the first electrode 410 moves down by the stepping motor 530, and the second lower lift 520 connected to the second electrode 420 moves up. The edge area of the backside of the substrate G is then placed on the second electrode 420 moving up. The second electrode 420 stops at a predetermined distance from the insulating member 200 in the upper portion of the chamber 100. A reactive gas flows into the space 314 of the inner electrode through the gas supply channel 110 formed in the chamber lid 100 b from the gas supplier 120 connected to the upper portion of the chamber 100. The reactive gas then flows into the chamber 100 through the gas injection nozzle 312 at a side of the inner electrode 310 as shown in FIG. 11. A ground potential is applied to the inner electrode 310, the outer electrode 320, and the first electrode 410, and an RF is applied to the second electrode 420, such that plasma P is generated.

The plasma P is generated in a space surrounded by the second electrode 420 where the RF is applied, the inner electrode 310 where the ground potential is applied, outer electrode 320, and first electrode 410, in detail, around the edge area of the upper surface, the side, and the central portion of the backside of the substrate G. Because the distance between the insulating member and the central region of the upper surface of the substrate is maintained at 1 mm or less, the plasma P is not generated. Therefore, the plasma P generated as described above removes particles and thin films accumulated on the edge area of the upper surface, the side, and the central portion of the backside of the substrate G.

Because the first electrode 410 has a smaller area than a conventional lower electrode, a separate lift member is not needed. The conventional lower electrode is provided with a separate lift member for supporting a substrate. That is, when the substrate is inserted into the chamber by an outer robot arm, a lift pin which is provided in the lower electrode moves up, and the substrate is placed on the lift pin. The substrate on the lift pin is then placed on the lower electrode as the lift pin moves down. On the contrary, according to the exemplary embodiment of the invention, when the substrate G is inserted into the chamber 100 by an outer robot arm (not shown), the first electrode 410 can support the lower portion of the substrate G without interference of the robot arm. Therefore, the substrate G can be placed on the first electrode 410 without the separate lift pin according to the exemplary embodiment of the present invention.

Although the lower electrode 400 includes the first electrode 410 and the second electrode 420 in the above configuration, the present invention is not limited thereto. That is, an intermediate electrode may be further provided between the inner electrode and the outer electrode located at the outermost region.

As shown in FIG. 12, a lower electrode 400 includes an inner electrode of a circular plate shape (hereinafter, referred to as a “first electrode”, 410), a ring-shaped intermediate electrode (hereinafter, referred to as a “second electrode”, 420) and a ring-shaped outer electrode (hereinafter, referred to as a “third electrode”, 430). Each of the electrodes is coaxially arranged. The inner circumference of the second electrode is spaced apart from the outer circumference of the first electrode 410 by a predetermined distance. The inner circumference of the third electrode is spaced apart from the outer circumference of the second electrode 420 by a predetermined distance.

The outer circumference of the first electrode 410 is disposed at a predetermined distance from the inner circumference of the second electrode 420. The outer circumference of the second electrode 420 is disposed at a predetermined distance from the inner circumference of the third electrode 430.

After a substrate is placed on the first electrode 410 and the reactive gas flows into the chamber through the inner electrode, the first electrode 140 moves up to be spaced apart by a predetermined distance from the insulating member in the upper portion of the chamber. An RF is applied to the first electrode 410, and a ground potential is applied to the inner electrode, outer electrode, second electrode 420, and third electrode 430. Therefore, plasma is generated between the first electrode 410 and the ground potential, i.e. around the edge area of the upper surface, the side, and the edge area of the backside of the substrate G; such that particles and thin films accumulated thereon are removed by the plasma.

Likewise, the second electrode 420 moves up and stops at a predetermined distance from the insulating member. The RF is applied to the second electrode 420 and the ground potential is applied to the inner electrode, outer electrode, first electrode 410, and third electrode 430. Therefore, plasma is generated between the second electrode 420 and the ground electrode, such that particles and thin films accumulated on the edge area of the upper surface, the side, and the backside of the substrate are removed by the plasma.

Similarly, the third electrode 430 moves up and stops at a predetermined distance from the insulating member. The RF is applied to the third electrode 430 and the ground potential is applied to the inner electrode, outer electrode, first electrode 410, and second electrode 420. Therefore, plasma is generated in a space surrounded by the third electrode 430 and the other electrodes to which ground potential is applied, such that the particles and thin films accumulated on the edge area of the upper surface, the side, and the central portion of the backside of the substrate G are removed by the plasma.

According to the above configuration, as the first electrode 410 moves up, the second and third electrodes 420, 430 move down; as the second electrode 420 moves up, the first and third electrodes 410, 430 move down; and as the third electrode 430 moves up, the first and second electrodes 410, 420 move down. However, the present invention is not limited thereto. That is, the second electrode 420 may move down while the first and third electrodes 410, 430 move up; and as the second electrode 420 moves up, the first electrode 410 and the third electrode 430 move down. Further, depending on processes, the first to third electrodes 410, 420, 430 may move up and down individually or in combination with one another.

Further, power may be applied to the electrodes as follows. As shown in FIG. 13, the first to third electrodes 410, 420, 430 are coaxially spaced apart from each other by predetermined distances, and a power distributor 480 is provided between the first electrode 410 and the third electrode 430. An RF power supply 450 and an RF matching device 460 are connected to the lower portions of the first electrode 410 and the second electrode 420. Furthermore, sensors 470 are provided between the RF matching device 460 and the first electrode 410, and between the RF matching device 460 and the second electrode 420.

The power distributor 480 is connected between the first electrode 410 and the third electrode 430. The power distributor 480 attenuates the power applied to the first electrode 410, i.e. the power applied to the first electrode 410 when a high-frequency power is applied to the third electrode 430. The power distributor 480, for example, may use a variable condenser or resistance etc., and preferably a variable condenser. Although the power distributor 480 attenuates the power applied to the first electrode 410 and then applies the power to the third electrode 430, the present invention is not limited thereto. The power distributor may amplify the power applied to the first electrode 410 and then apply the power to the third electrode 430. The above power distributor 480 can appropriately control plasma generated around a substrate G by regulating the high-frequency power that is applied to the first electrode 410 and the third electrode 430. Therefore, deformation of the substrate G can be prevented during the process and etching uniformity around the edge area and the central portion of the backside of the substrate is increased.

The sensors 470 are provided between the first electrode 410 and the RF matching device 460, and between the second electrode 420 and the RF matching device 460. The sensor 470 detects the amount of power that is supplied from the RF power supply and then distributed to the first electrode 410 and the second electrode 420. The detected power is monitored and compared by an external device.

Further, gas injection holes may be formed in a plurality of electrodes to feed a reactive gas into the chamber, of which configuration is as follows. As shown in FIG. 14, a lower electrode 400 includes a first electrode 410 and a second electrode 420 that is coaxially disposed by a predetermined distance from the first electrode 410.

The first electrode 410 is formed in a circular plate shape, and a plurality of first gas injection holes 412 is formed along the outer circumference of the first electrode 410. Further, a first gas supply line 414 is connected to the lower portion of the first electrode 410. A predetermined space (not shown) is formed in the first electrode 410, and the plurality of first gas injection holes 412 are formed along the outer circumference of the first electrode 410 to communicate with the predetermined space. The first gas supply line 414 also communicates with the predetermined space in the first electrode 410. Therefore, a reactive gas supplied through the first gas supply line 414 passes through the predetermined space in the first electrode 410 and then injected into the chamber through the first gas injection holes 412 formed along the outer circumference of the first electrode 410. The second electrode 420 is formed in a ring shape so that the inner circumference is spaced apart from the outer circumference of the first electrode 410 by a predetermined distance. The first and second electrodes 410, 420 are coaxially arranged. A plurality of gas injection holes 424 is formed along the inner circumference of the second electrode 420. Further, a second gas supply line 426 is connected to the lower portion of the second electrode 420. Similar to the first electrode 410, a predetermined space (not shown) communicating with the second gas injection holes 424 is formed in the second electrode 420. The predetermined space communicates with the second gas supply line. Therefore, the reactive gas supplied through the second gas supply line 426 passes through the space in the ring-shaped second electrode 420 and then is injected into the chamber through the second gas injection holes 424.

When the substrate is placed on the first electrode 410 and then spaced apart from an insulating member in the upper portion of a chamber by a predetermined distance, the reactive gas is uniformly injected through the first gas injection holes 412 formed along the outer circumference of the first electrode 410. The injected reactive gas is uniformly distributed along the edge area of the backside of the substrate, such that plasma can be uniformly generated. Meanwhile, when the substrate is placed on the second electrode 420 and then spaced apart from the insulating member in the upper portion of the chamber, the reactive gas is uniformly injected through the second gas injection holes 424 formed along the inner circumference of the second electrode 420. The injected reactive gas is uniformly distributed around the central region of the backside of the substrate G, such that plasma can be uniformly generated. Density of the plasma can be controlled by regulating the amount of reactive gas injected through the first and second gas injection holes 412, 424. Therefore, the accumulated particles and thin films can be removed more effectively.

The first and second gas injection holes 412, 424 may be connected to one gas supply line or respective gas supply lines. A heating member (not shown), for example a heater, for heating the first and second electrodes 410, 420 may be further provided in the first and second electrodes 410, 420.

In the above configuration, the reactive gas is supplied to the first and second electrodes 410, 420 in the lower portion of the chamber, and thereby particles and thin films accumulated on the backside of the substrate can be effectively removed at any positions in the chamber irrespective of a position of the substrate G.

When the lower electrode includes at least three electrodes, they may be configured as follows. As shown in FIG. 15, a lower electrode 400 is formed to have a circular plate shape and includes a first electrode 410, a second electrode 420 and a third electrode 430. The first electrode is provided with first gas injection holes 412 along an outer circumference thereof. The second electrode 420 is formed to have a ring shape and coaxially disposed at a predetermined distance from the outer circumference of the first electrode 410. Second gas injection holes 424 are formed along the inner and outer circumferences of the second electrode 420. The third electrode 430 is formed to have a ring shape and coaxially disposed at a predetermined distance from the outer circumference of the second electrode 420. Third gas injection holes 432 are formed along the inner circumference of the third electrode 420. Configurations of the first and third electrodes 410, 430 are the same as that shown in FIG. 11 and the corresponding description will be omitted.

The second electrode 420 is formed in a ring shape with a center cut vertically. The inner diameter is determined such that the first electrode 410 can be inserted, and the outer diameter is determined such that the second electrode 420 can be inserted into the third electrode 430. The second gas injection holes 424 are formed along the inner and outer circumference of the second electrode 420 to communicate with each other. A gas supply line 426 is connected to the lower portion of the second electrode 420 to communicate with the second gas injection holes 424. The second gas injection holes 424 are formed along the inner and outer circumference of the second electrode 420 such that they are connected with each other in the above configuration, but the gas injection holes may be independently formed.

When a substrate is placed on the second electrode 420 and then disposed at a predetermined distance from an insulating member in the upper portion of a chamber, the reactive gas is injected along the inner and outer circumference of the second electrode through the second gas injection holes 424. The injected reactive gas is uniformly distributed along the central portion of the backside and the edge area of the substrate. The uniformly distributed reactive gas generates uniform plasma, whereby particles and thin films accumulated on the edge and the center portions of the backside of the substrate can be effectively removed. Further, density of the plasma can be controlled by regulating the amount of the injected reactive gas.

The lower electrode 400 is divided into three electrodes in the above configuration, but the present invention is not limited thereto. The lower electrode 400 may be separated into a plurality of electrodes, i.e. four or more electrodes. When the lower electrode is separated into three or more electrodes, the innermost electrode may have gas injection holes only along the outer circumference thereof, and the outermost electrode may have gas injection holes only along the inner circumference thereof.

When the electrode is separated into a plurality of electrodes, the outermost electrode, i.e., the third electrode in this case may be configured as follows. Of course, the outermost electrode is not limited to the third electrode, and may be Nth electrode according to the number of electrodes. The third electrode is exemplified as the outermost electrode hereafter.

Referring to FIGS. 16 and 17, the third electrode 430 is formed in a ring shape having a through hole at the center thereof, and provided with third gas injection holes 432 along the inner circumference of the third electrode 430. A third gas supply line 434 is connected to the lower portion of the third electrode 430 to communicate with the third gas injection holes 432.

The diameter of the third electrode 430 is larger than that of the substrate G, and a seating portion is formed on the third electrode 430 to place the substrate G onto. In detail, the upper surface of the third electrode 430 includes a first plane 436 and a second plane 438. The second plane 438 is parallel to the first plane 436. The first and second planes 436, 438 are connected by an inclined plane downwardly extending from the first plane. Therefore, the edge area of the backside of the substrate G is placed on the second plane 438, and the side of the substrate G faces the inclined plane between the first plane 436 and the second plane 438.

In the above configuration, the seating portion is formed in the third electrode 430 so that the substrate G can be placed thereon. The seating portion prevents the substrate G from being separated from the third electrode 430 due to the injecting pressure of the reactive gas when the reactive gas is injected to the backside of the substrate G, the reactive gas being supplied through the third gas injection holes 432 formed in the third electrode 430.

In the above configuration, the first and second lower lifts 510, 520 that are respectively connected to the first and second electrodes 410, 420 are formed like a seesaw, and the first and second electrodes 410, 420 alternately move up and down to remove particles and thin film accumulated on the substrate G. However, the first lower lift 510 may be connected to the first electrode 410, and an upper lift 600 may be connected to the insulating member 200 to remove particles attached and thin films accumulated on the substrate G.

FIG. 18 is a cross-sectional view of a plasma processing apparatus according to a second exemplary embodiment of the present invention. FIGS. 19 and 20 are cross-sectional view illustrating an operation of the plasma processing apparatus according to the second exemplary embodiment of the present invention.

Referring to FIG. 18, a plasma processing apparatus includes a chamber 100; an insulating member 200 disposed in the upper portion of the chamber 100; a ground electrode 300 provided at the upper portion of the sidewall of the chamber 100; a lower electrode 400 where a substrate G is placed; an upper lift member, i.e. an upper lift 600 and a first lower lift 510 for moving up and down the insulating member 200 and the lower electrode 400. The plasma processing apparatus further includes a chamber liner 700 provided at the inner wall of the chamber 100; a focus ring 710 disposed along the outer circumference of the lower electrode 400; a vent plate 800 disposed between the outer circumference of the lower electrode 400 and the inner wall of the chamber 100. Description on an overlapping configuration will be omitted.

The upper portion of the insulating member 200 is fixed by a support 230. The upper lift 600 is connected to the support 230 for moving the support 230 up and down. The upper lift 600 moves the insulating member 200 fixed to the support 230 to be spaced apart from the lower electrode 400 by a predetermined distance.

The first lower lift 510 is connected to the bottom of the first electrode 410 and moves the first electrode 410 up and down. An electrode support 900 connected to the floor of the chamber 100 is formed at the bottom of the second electrode. The second electrode 420 is spaced apart from the bottom of the chamber 100 by a predetermined distance by the electrode support 900.

The chamber liner 700 is formed along the inner wall of the chamber 100. The upper portion of the chamber liner 700 is electrically connected to the lower portion of the outer electrode 320. The chamber liner 700 protects the side wall of the chamber 100 from the plasma and a ground potential is applied to the chamber liner 700 similar to the outer electrode 320.

The focus ring 710 is formed in a ring shape along the outer circumference of the lower electrode 400. The focus ring 710 focuses plasma onto the substrate G when a reactive gas changes into the plasma.

The vent plate 800 is a circular plate of which center is bored and includes a through hole 810 vertically formed through the plate. The vent plate 800 is disposed between the lower electrode 400 and the inner wall of the chamber 100, and in detail, connects the outer circumference of the focus ring 710 to the inner wall of the chamber 100, whereby the inside of the chamber is divided into upper and lower portions. That is, the vent plate 800 controls pressure to uniformly distribute a reactive gas in the chamber 100, by which uniform plasma is generated. Therefore, local concentration of plasma in the chamber 100 can be prevented.

A protruding electrode 820 may be further provided on a side, i.e. the upper surface of the vent plate 800. The protruding electrode 820 makes a chamber pressure uniform and functions as an electrode by a ground potential applied thereto. The protruding electrode 820 may be coupled with the vent plate 800 or integrally formed with the vent plate 800. The ground potential may be respectively applied to the vent plate 800 and the protruding electrode 820. The ground potential may be simultaneously applied to the vent plate 800 and the protruding electrode 820.

As shown in FIG. 19, when the substrate G is placed on the first electrode 410, the first lower lift 510 connected to the bottom of the first electrode 410 moves up and the first electrode 410 is disposed at a predetermined distance from the insulating member 200 at the upper portion in the chamber 100.

Subsequently, the reactive gas flows into the chamber 100 through the inner electrode 310. A ground potential is applied to the inner electrode 310, the outer electrode 320, and the second electrode 420, and RF is applied to the first electrode to generate plasma in the chamber 100. Therefore, particles and thin films accumulated on the edge area of the upper surface, the side, and the edge area of the backside of the substrate G are removed by the plasma.

As shown in FIG. 20, when the substrate G is placed on the second electrode 420, the insulating member 200 is disposed at a predetermined distance from the second electrode 420 by the upper lift 600 connected to the insulating member 200. Subsequently, the reactive gas is supplied into the space 314 in the inner electrode 310 through the gas supply channel 110 formed in the chamber lid 100 b from the gas supplier 120 connected to the upper portion of the chamber 100. The reactive gas then flows into the chamber 100 through the gas injection nozzle 312 at a side of the inner electrode 310.

The ground potential is applied to the inner electrode 310 and the outer electrode 320 and therefore the ground potential is applied to the chamber liner 700 electrically connected to the outer electrode 320. In addition, the ground potential is also applied to the first electrode 410, and RF is applied to the second electrode 420 to generate plasma P in the chamber 100.

The plasma P is generated in a space surrounded by the second electrode 420, the chamber liner 700 and the protruding electrode 820. The ground potential is applied to the second electrode 420 and the chamber liner 700. Therefore, the plasma P is generated near the edge area of the upper surface, the side, and the central portion of the backside of the substrate G where the ground potential is applied. The plasma P is not generated in the region between the insulating member 200 and the central portion of the upper surface of the substrate G because the distance between the insulating member 200 and the central portion of the upper surface of the substrate G is maintained at 1 mm or less. Therefore, the plasma P generated as described above removes particles and thin films accumulated on the edge area of the upper surface, the side, and the central portion of the backside of the substrate G.

According to the above configuration, the upper lift 600 is connected to the insulating member 200 and the first lower lift 510 is connected to the first electrode 410. Thereby, particles and thin films accumulated on the edge area of the upper surface, the side, and the backside of the substrate G can be effectively removed.

An apparatus according to the above configuration can be easily controlled compared to the lift member according to the first exemplary embodiment of the present invention. The lift member according to the first exemplary embodiment is used for moving the first and second electrodes. The components are therefore concentrated in the lower portion of the chamber and the control of the lift member is not easy, whereas the lift member according to the second exemplary embodiment can avoid the difficulties.

Although a lower lift is connected to the lower portion of a first electrode and an electrode support is connected to a second electrode in the above description, the electrode support may be connected to the first electrode and the lower lift may be connected to the second electrode.

Although a liner which is electrically connected to an outer electrode is provided in the chamber and the ground potential is applied to the liner in the above description, an electrode to which the ground voltage is applied may be formed instead of the liner.

Although a plurality of lower electrodes is coaxially disposed in the above description, the present invention is not limited thereto. The lower electrodes may be arranged in one direction.

Although the process is performed by employing a seesaw structure to a plurality of divided lower electrodes in the above description, but the present invention is not limited thereto. The plurality of electrodes may simultaneously move up depending on various processes.

Although a semiconductor wafer is used as a substrate in the plasma processing apparatus of the above description, but a glass substrate for a flat panel display may be used as a substrate.

FIG. 21 is a sectional view of a plasma processing apparatus in accordance with a third exemplary embodiment. FIG. 22 is a perspective view of a lower electrode shown in FIG. 21.

Referring to FIGS. 21 and 22, a plasma processing apparatus in accordance with the third exemplary embodiment includes: a chamber 1100; an insulating plate 1520 disposed at an upper region in the chamber 1100; a ground electrode 1540 provided at an upper portion of a sidewall of the chamber 1100; a lower electrode 1510 on which a substrate G is seated; an upper lift 1551 configured to lift up/down the insulating plate 1520; and a lower lift 1552 configured to lift up/down the lower electrode 1510. Also, the plasma processing apparatus may further includes: a first gas supply means 1560 configured to supply a first gas to the upper region in the chamber 1100; and a second gas supply means 1570 configured to supply a second gas through the lower electrode 1510.

Herein, the first gas supply means 1560 includes: a first gas supply unit 1561 configured to store the first gas; and a first gas supply channel 1562 configured to supply the first gas into the chamber 1100. Also, the second gas supply means 1570 includes: a second gas supply unit 1571 configured to store the second gas; and a second gas supply channel 1572 configured to supply the second gas to the lower electrode 1510.

The insulating plate 1520 is installed on a bottom surface of a support plate 1530. The upper lift 1551 is coupled with the center of a top surface of the support plate 1530 and installed at a top wall of the chamber 1100, so that the upper lift 1551 can move up and down within a predetermined range. The support plate is formed in a shape of a cylinder having a sidewall protruding downward along the edge, and the insulating plate 1520 is installed in an inner space defined by the sidewall. Also, a guide hole 1531 for guiding light of a laser sensor 1410 is installed at the edge of the support plate 1530 or insulating plate 1520. Specifically, the guide hole 1531 may be formed to penetrate the space between the insulating plate 1520 and the sidewall of the support plate 1530. Herein, the guide hole 1531 may be formed to penetrate only the sidewall of the support plate 1530 or to penetrate both of the support plate 1530 and the insulating plate 1520.

The ground electrode 1540, which is provided at the upper portion of the sidewall of the chamber 1100, is formed in a shape of a circular ring. The ground electrode 1540 includes an inner electrode 1541 and an outer electrode 1542 that are grounded, respectively. The top region of the inner electrode 1541 is connected with the first gas supply channel 1562 formed in the top wall of the chamber 1100, and a predetermined space is provided inside the inner electrode 1541. Also, a plurality of gas injection holes connected with the predetermined space is formed at one side of the sidewall of the inner electrode 1541. That is, the first gas flows through the first gas supply channel 1562 which is formed in the top wall of the chamber 1100 into the predetermined space formed at the inside of the inner electrode 1541. The first gas introduced into the predetermined space flows into the chamber 1100 through the gas injection holes formed at the sidewall of the inner electrode 1541. The outer electrode 1542 is formed to be adjacent to an upper portion of the sidewall of the chamber 1100, more specifically, to the bottom of the inner electrode 1541. Thus, when the process is started, the ground electrode 1540 is disposed to be adjacent to an edge region of the substrate G. That is, the ground electrode 1540 is disposed at the end region of the substrate G in order to etch particles and deposits which are present in the top edge region, the side region, and the backside of the substrate G, by using plasma. Meanwhile, the inner electrode 1541 and the outer electrode 1542 formed as a single electrode may be coated with a dielectric layer for protection.

The lower electrode 1510 may be divided into a plurality of electrodes 1511, 1512, 1513. RF voltages 1591, 1592 may be supplied to the electrodes 1511, 1513 which are odd-numbered from the center toward the periphery of the substrate G, and a ground voltage may be supplied to the other electrode 1512. Herein, the electrodes 1511, 1513 to which the RF voltages 1591, 1592 are supplied may be fixed and the other electrode 1512 may move up and down. For example, the lower electrode 1510 includes: a first electrode 1511 which has a shape of a circular pillar and is disposed corresponding to the center of the substrate G; and second and third electrodes 1512, 1513 that have a shape of a circular ring and are disposed around the first electrode 1511 in an ascending order of diameters. Herein, the RF voltages 1591, 1592 are supplied to the first electrode 1511 and the third electrode 1513. And the ground voltage is supplied to the second electrode 1512. Herein, the first and third electrodes 1511, 1513 to which the RF voltages 1591, 1592 are supplied are respectively fixed by the support 1580 to a bottom wall of the chamber 1100, and the second electrode 1512 is connected with the lower lift 1552 to move up and down. Thus, the RF voltages 1591, 1592 can be stably supplied to the first electrode 1511 and the third electrode 1513, and some region of the backside of the substrate G and the remaining region can be alternately exposed according to the up/down movement of the second electrode 1512. Therefore, particles and deposits that are present in the entire region of the backside of the substrate G can be removed. Although, in the above description, the lower electrode 1510 is divided into three electrodes 1511, 1512, 1513, the present invention is not limited thereto. That is, the lower electrode 1510 may include four or more electrodes.

Herein, the outer electrode may have a larger diameter than the inner electrode in order to stably support the substrate and to prevent deformation of the substrate. For example, if the lower electrode includes first, second and third electrodes disposed from the center toward the periphery of the substrate G, it may be preferable that the diameter of the first electrode is approximately 35 to 55% of the diameter of the outermost electrode (i.e., the third electrode) and the diameter of the second electrode is approximately 56 to 75% of the diameter of the outermost electrode. If the lower electrode includes first, second, third and fourth electrodes disposed from the center toward the periphery of the substrate G, it may be preferable that the diameter of the first electrode is approximately 35 to 45% of the diameter of the outermost electrode (i.e., the fourth electrode), the diameter of the second electrode is approximately 46 to 60% of the diameter of the outermost electrode, and the diameter of the third electrode is approximately 61 to 75% of the diameter of the fourth electrode. If the lower electrode includes first, second, third, fourth and fifth electrodes disposed from the center toward the periphery of the substrate G, it may be preferable that the diameter of the first electrode is approximately 30 to 40% of the diameter of the outermost electrode (i.e., the fifth electrode), the diameter of the second electrode is approximately 41 to 50% of the diameter of the outermost electrode, the diameter of the third electrode is approximately 51 to 60% of the diameter of the outermost electrode, and the diameter of the fourth electrode is approximately 61 to 75% of the diameter of the outermost electrode

Also, a plurality of gas injection holes 1511 a, 1512 a, 1513 a are provided on the surfaces of the lower electrodes 1511, 1512, 1513. That is, as illustrated in FIG. 22, a plurality of gas injection holes 1511 a, 1512 a, 1513 a are formed on the top surfaces and the side surfaces of the lower electrodes 1511, 1512, 1513. The gas injection holes 1511 a, 1512 a, 1513 a are connected with the second gas supply channel 1572 to inject the second gas which is provided from the second gas supply unit 1571, toward the rear of the substrate G. Therefore, the second gas can be supplied into the chamber 1100 simultaneously with or separately from the first gas supplied to the inner upper region of the chamber 1100, and thus a variety of process controls are possible. Of course, at least one of the first and second gases includes a reaction gas for removing particles on the substrate G, and they may use the same gas or different gases. Although a plasma processing apparatus of an RIE type having a plurality of lower electrodes according to an exemplary embodiment of the present invention is described in the above description, but the present invention is not limited thereto. The present invention can also be applied to any plasma processing apparatus employing inductive coupled plasma (ICP); capacitively coupled plasma (CCP); electron cyclotron resonance (ECR) plasma using a microwave; surface wave plasma (SWP); and remote plasma system (RPS).

As described above, the lower electrode of the exemplary embodiments of the present invention includes a plurality of electrodes and the electrodes are alternately lifted up and down on a group-by-group basis, so that particles and deposits that are present not only on the top and bottom edges and the side surface of the substrate but also on the entire backside of the substrate can be effectively removed.

Also, the lower electrode of the exemplary embodiments of the present invention includes a plurality of electrodes, and the ground voltage and the RF voltage are alternately supplied to the electrodes of the lower electrode, so that plasma can be uniformly formed in a large area. Therefore, the present invention can be applied not only to small/medium-sized substrates but also to large-area substrates.

Further, the lower electrode of the exemplary embodiments of the present invention includes a plurality of electrodes, and some of the electrodes move the substrate to loading/unloading position. Therefore, separate substrate lifting means is not necessary and the configuration of the lower electrode can be further simplified.

The guide hole is provided at the edge of the upper electrode which is disposed in an upper region of the inside of the chamber, so that the position of the substrate can be accurately detected without interference of the upper electrode. Therefore, the alignment error of the substrate can be further reduced and the distance between the upper electrode and the lower electrode can be controlled more accurately, thereby the process efficiency can be maximized.

Although the plasma processing apparatus has been described with reference to the specific embodiments, it is not limited thereto, but is defined by the appended claims. Therefore, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention defined by the appended claims. 

1. A plasma processing apparatus comprising: a chamber; an insulating plate provided in an upper region in the chamber; a ground electrode provided on a sidewall of the chamber and supplied with a ground voltage; and a lower electrode provided in a lower region in the chamber on which a substrate is seated, wherein the lower electrode comprises a plurality of electrodes, and an RF voltage and the ground voltage are alternately supplied to the adjacent two electrodes, respectively.
 2. The plasma processing apparatus of claim 1, wherein the electrode(s) to which the RF voltage is supplied is fixed, and the other electrode(s) is driven to move up and down.
 3. The plasma processing apparatus of claim 1, wherein the electrode(s) to which the ground voltage is supplied is fixed, and the other electrode(s) is driven to move up and down.
 4. The plasma processing apparatus of claim 1, wherein the electrodes of the lower electrode are concentric and spaced apart from each other by a predetermined distance.
 5. The plasma processing apparatus of claim 4, wherein the electrodes of the lower electrode comprise first, second and third electrodes arranged from the center toward the periphery of the substrate, the diameter of the first electrode is approximately 35 to 55% of the diameter of the third electrode, and the diameter of the second electrode is approximately 56 to 75% of the diameter of the third electrode.
 6. The plasma processing apparatus of claim 4, wherein the electrodes of the lower electrode comprise first, second, third and fourth electrodes arranged from the center toward the periphery of the substrate, the diameter of the first electrode is approximately 35 to 45% of the diameter of the fourth electrode, the diameter of the second electrode is approximately 46 to 60% of the diameter of the fourth electrode, and the diameter of the third electrode is approximately 61 to 75% of the diameter of the fourth electrode.
 7. The plasma processing apparatus of claim 4, wherein the electrodes of the lower electrode comprise first, second, third, fourth and fifth electrodes arranged from the center toward the periphery of the substrate, the diameter of the first electrode is approximately 30 to 40% of the diameter of the fifth electrode, the diameter of the second electrode is approximately 41 to 50% of the diameter of the fifth electrode, the diameter of the third electrode is approximately 51 to 60% of the diameter of the fifth electrode, and the diameter of the fourth electrode is approximately 61 to 75% of the diameter of the fifth electrode
 8. The plasma processing apparatus of claim 1, further comprising a substrate sensor provided on the chamber to sense the substrate, wherein at least one guide hole is formed in the insulating plate to guide light output from the substrate sensor toward the substrate. 